Life Characteristics

• Biology: The study of life• Life exists within the

biosphere– Biosphere: layer of Earth

where life exists• Organism: anything that can

carry on the processes of life• Species: organisms that can

create fertile offspring• Biodiversity

– Over 2 million known species

– Life more diverse along equator

• Oldest life (bacteria) = 3.5 billion years old

What is Biology?

Can a cat and dog create a hybrid?

Are centaurs possible?Humans and Chimps share over 98% of our DNA. Can we reproduce with

each other?Australian Bacteria fossils

Why?

Polar Bears: Are they part of biology?

Plants: Are they part of biology?

Bacteria: Are they part of biology?

Mountains: Are they part of biology?

The Sun: Is it part of biology?

Water: Is it part of biology?

Molecules: Are they part of biology?

• All life has a few common characteristics

1) Made from cells– Cell = most basic

unit of life capable of carrying on life processes

– Cells are specialized for specific duties• Ex: Red blood

cells carry O2

Life Characteristics

White blood cell

Nerve cell

2) Requires energy– Energy = ability to do

work or cause change– Energy controls

metabolism (ability to break down materials)

– Two categories:• Autotrophs:

– Create sugars using energy from the sun

– Ex: Photosynthetic plants & algae

• Heterotrophs:– Consume others for

energy– Ex: Fungi & animals

Life Characteristicssunlight

sugaroxygen

sugarsugar

sugar

sugarsugar

3) Responds to environment– Stimulus =

environmental factors• Stimulus examples:

Sound, light, touch, sight, taste, smell

Life Characteristics!*%!?%&#

• 4) Reproduces and develops– Reproduction: Passing of genetic

material (DNA) to next generation

– Two Types of Reproduction:a) Asexual reproduction• Offspring is genetically identical

to parent• Ex: bacteria, protista, some

plants & animalsb) Sexual reproduction• Offspring is a genetic mixture of

two parents• Ex: Most fungi, plants, animals

Life CharacteristicsBudding: individual pops

off from the parent

Single celled life will simply split into two organisms

1) Made of cells

2) Requires energy

3) Responds to environment

4) Reproduces

5) Develops

Is Fire Alive?no

yes

yesyes

yes

So are fires alive?

No!

30 seconds to discuss with your neighbor:

Is fire alive?

1) Made of cells

2) Requires energy

3) Responds to environment

4) Reproduces

5) Develops

Are Cars Alive?no

yes

no

no

yes

So are cars alive?

No!

Review1) Name 4 features common to all life?2) Which type of reproduction creates identical offspring?3) In general, which group of life performs photosynthesis to

make their own food?4) What is the ability to break down food called?5) A loud noise or a sharp pain is an example of a _____.6) Which type of reproduction creates genetic diversity?7) Why is biodiversity greatest at the equator?8) Vocabulary: Biology, Biosphere, Biodiversity, Species, Cell,

Energy, Metabolism, Heterotroph, Autotroph, Stimulus, Asexual reproduction, Sexual reproduction